تأثير معاملة بذور الحنطة بالبكتيريا Azotobacter chroococcum و Azospirillum brasilense والاشعة فوق البنفسجية في حماية نبات الحنطة من الاصابة بمرض الندبة السوداء

Abstract

This study was conducted in one of the wheat fields in Al-Hira / Najaf governorate with the aim of using environment-friendly technology using UV-C with short wavelength 253nm in seed sterilization, as well as Azospirillum brasilense and Azotobacter chroococcum bacteria to protect wheat plant form incidence of black scar. The results of field survey in the some fields of Najaf province showed that the rate of infection with a black scar on wheat caused by fungus Alternaria alternata ranged between 13-70% , The results of the test of the effect of isolates of the fungus Alternaria alternata on the proportion of germination of wheat seeds that the isolation of the fungus negatively affected the seed germination where the proportion of germination in seeds isolated treatment 3AS-Kufa was decreased to 71% and Al- Najaf isolate to 66% and ASAAQEE isolate to 76% compared to control treatment which the percentage of germination was 80%. The results of the study showed that UV radiation has an inhibitory effect on the number of live units in one ml of Alternata alternaria and Azotobacter chroococcum and Azospirillum brasilense where it reached 8.6x106, 8.5x106, 8.3x106, 315x106, 487x106 and 752x106 respectively. Compared with control treatment where it reached 9.4x 106, 9.8x 106, 9.1x 106, 464x 106, 424x 106 and 768x106 respectively. Laboratory conditions, this study demonstrated the ability of Azotobacter chroococcum and Azospirillum brasilense to inhibit the growth of Alternaria alternata where the percentage of inhibition for the isolate 3AS-Kufa was 80.35%, 80.58%, 80.35%, respectively, and Al-Najaf isolate 79.64%, 80.70%, 80.23% respectively, and for the ASAAQEE isolate was 80.56%,% 80.00 and 80.47% respectively .